1. Field of the Invention
The present invention relates to liquid dispensers and tanks for holding and dispensing liquids, and more particularly to a liquid beverage dispenser including a liquid dispensing chamber, a liquid storage chamber, a pump for pumping liquid beverage from the storage chamber to the dispensing chamber when the liquid level in the dispensing chamber is low, and a liquid level sensor for measuring the liquid level in the dispensing chamber and for activating the pump when the liquid level is low.
2. Description of the Prior Art
Liquid beverage dispensers are commonly used by restaurants and other retail outlets for displaying and dispensing liquid beverages such as frozen ice drinks and slush drinks. These liquid beverage dispensers typically include a transparent liquid dispensing chamber positioned in the customers' view for holding and dispensing a supply of liquid beverage. To maintain a sufficient source of beverage for sale, the dispensing chamber must be monitored and refilled when the liquid level drops too low. Liquid level sensors are often provided in these dispensing chambers for measuring the liquid level and for prompting the filling of the chamber when the liquid level is low.
Prior art liquid beverage dispensers typically include a pair of electroprobes for measuring the liquid level in the dispensing chamber. The electroprobes extend from the top of the dispensing chamber into the liquid contained in the chamber. The liquid in the liquid dispensing chamber acts as a conductor for closing an electrical circuit between the electroprobes. When the liquid level drops below the electroprobes, the circuit is broken, thus the electroprobes sense that the liquid level in the dispensing chamber is low.
These electroprobe sensing devices suffer from several limitations that limit their utility. For example, the electroprobes often give false level measurement readings. Whenever there is liquid between the electroprobes, the electrical circuit between the probes is closed. This causes problems because dispensing chambers are commonly used for storing and dispensing frozen liquids. Often the liquid beverage becomes frozen and adhered between the probes. This causes the electrical circuit to remain closed even after the unfrozen liquid drops below the level of the electroprobes.
Another limitation of prior art beverage dispensers is that the electroprobes must be mounted below specially designed hoods. Additionally, since the electroprobes extend from the top of the dispenser, the dispenser must be filled from the bottom to prevent false level readings.
Another limitation of electroprobes is that they are unsightly. Most liquid beverage dispensers include a transparent dispensing chamber that places the liquid beverage in open view for enticing consumers to buy the product. To effectively measure the level of the liquid dispensing chambers, the electroprobes must extend from the top of the chamber into the liquid. Thus, the electroprobes are in constant view and detract from the enticing look of the transparent dispensing chambers.
A further limitation of electroprobes is that they are costly. Electroprobes measuring devices include a pair of large steel electroprobes and associated circuitry for measuring conductivity between the probes. These electroprobes increase the overall cost of the liquid beverage dispensers.
Another limitation of prior art liquid beverage dispensers is that many do not have means for automatically refilling the dispensing chamber when the liquid level therein drops below a predetermined level.
Accordingly, there is a need for an improved liquid beverage dispenser that overcomes the limitations of the prior art.